Researchers in
Belgium report that HIV may have become weaker since the
late 1980s and may spread less rapidly in the body than the
virus did 15 years ago, AIDSmap.com reports. Studying
HIV-1 isolates taken from treatment-naive patients in
both 1986–1989 and in 2002–2003, the
researchers report that HIV appears to have become less
virulent—HIV from the 1980s was able to infect
immune system cells and kill them much more
effectively than virus collected from HIV patients today.

The researchers,
writing in the October 15 edition of the journalAIDS, report that the HIV viral fitness from the
most recent samples had a mean replicative fitness of just
55% of that from samples from the 1980s. Viral fitness
is a measurement of how easily and how quickly HIV is
able to infect human cells and begin making copies of
itself. The scientists theorize that the virus may slowly
lose its ability to easily and quickly replicate as it
mutates to develop stronger defenses against immune
system attacks against it.

The researchers
say their findings are the first to suggest that HIV may
weaken over time. If the data holds true and HIV continues
to weaken, it could evolve within the next 50 to 60
years to a point where it no longer causes deaths in
humans, the researchers theorize.

But some
scientists warn that even though HIV may be weakening, it
still remains contagious and deadly. Marco Vitoria, an
AIDS expert at the World Health Organization, also
points out that other diseases, like tuberculosis and
syphilis, have weakened over thousands of years but
still remain deadly, Bloomberg News reports. "Attenuation
isn't new in the natural history of many other
infectious diseases and is a very slow process, to be
measured not in years but in generations," he told the
news service. (Advocate.com)